On Tue, Sep 30, 2014 at 12:48 AM, Junio C Hamano <[email protected]> wrote: > Duy Nguyen <[email protected]> writes: > >> On Sun, Sep 28, 2014 at 2:50 PM, Ben Walton <[email protected]> wrote: >>> Oracle Studio compilers don't allow for static variables in functions >>> that are defined to be inline. GNU C does permit this. Let's reference >>> the C99 standard though, which doesn't allow for inline functions to >>> contain modifiable static variables. >>> >>> Signed-off-by: Ben Walton <[email protected]> >>> --- >>> trace.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/trace.c b/trace.c >>> index b6f25a2..4778608 100644 >>> --- a/trace.c >>> +++ b/trace.c >>> @@ -385,7 +385,7 @@ static inline uint64_t gettimeofday_nanos(void) >>> * Returns nanoseconds since the epoch (01/01/1970), for performance >>> tracing >>> * (i.e. favoring high precision over wall clock time accuracy). >>> */ >>> -inline uint64_t getnanotime(void) >>> +uint64_t getnanotime(void) >>> { >>> static uint64_t offset; >> >> Would moving this offset outside getnanotime() work? > > I am not sure what the definition of "work" is. > > The function computes the difference between the returned value from > gettimeofday(2) and a custom highres_nanos() just once and returns > the value it got from gettimeofday the first time, and then for > subsequent calls massages the returned value from highres_nanos() to > be consistent with the value returned from gettimeofday using the > offset it computed in the first call. > > If we have two copies of this function, two independent probes to > these pair of underlying functions will be made to compute their > offsets.
Hmm.. no. Even if the function is inlined in multiple places, inline code still points to the same "offset" variable. So the gettimeofday_nanos()/highres_nanos() pair should only be called once. Tested with gcc. -- Duy -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
